the tune of “happy birthday to you” originated from which 19th-century song?

The tune of "Happy Birthday to You" originated from the 19th-century song "Good Morning to All," composed in 1893 by sisters Patty Smith Hill, a kindergarten teacher, and Mildred Jane Hill, a pianist and composer. The original song "Good Morning to All" was intended as a simple greeting song for children, with different lyrics than the "Happy Birthday" song we know today. The birthday lyrics were later added to this melody, transforming it into the famous birthday song.